M2M, the abbreviation of Machine to Machine, refers to a type of service for communication between one machine and another. The Internet of Things (IOT) refers to an application of M2M to a wide area network, particularly a mobile operator network, where a radio network of a mobile network operator acts as a platform to offer machine to machine radio data transmission services of industry users through specialized industry User Equipments (UEs) in numerous transmission schemes (Code Division Multiple Access (CDMA)/Global System for Mobile communication (GSM)/Short Message Service (SMS), etc.)
M2M/IOT services with a potential market are widely geographically distributed, and can be deployed at any network reachable location for real unattended watching instead of costly attended watching, which may be of both great significance and a great potential market value to information acquisition of electric power, water conservancy, oil exploitation, ore exploitation, environment conservancy, weather, tobacco, finance and other industries.
The use of a radio network for communication is one of preferred solutions for widely distributed M2M UEs, and data information acquired by sensors is typically transmitted over a General Packet Radio Service (GPRS) network for some existing industry applications, e.g., remote metering, water level monitoring, etc. There is a pressing demand for a radio network along with the development of M2M applications.
When a large number of M2M UEs access a network densely, there will be a considerable load on both a radio network and a core network, and consequently there will be inevitable congestion and an increase in failure ratio of inter-human communication. However, only one wait time is carried in a Radio Resource Control (RRC) Connection Rejection message in the prior art without distinguishing between a Core Network (CN) overload and a Radio Access Network (RAN) overload. On one hand, the wait time is so short, for example, 16 seconds in a Long Term Evolution (LTE) system, that the UEs will access the network too frequently, which may discourage network congestion from being alleviated; and on the other hand, CN congestion and RAN congestion can not be treated differently, thus resulting in a too rough granularity of access control.